Black cotton soils and other expansive soils have typical characteristics of shrinkage and swelling due to moisture movement through them. Black cotton soils and other expansive soils are dangerous due to their shrinkage and swelling characteristics.

• Where the depth of clay layer is large, the foundation should be prevented from coming in contact with the soil. In addition to this, The property of the soil as per reports have very poor bearing capacity, ranging from 5 t/m2 to 10 t/m2.

Excavatiion can be done wider and deeper foundation trench and interposing layer of sand around and beneath the footing.

The foundation should be taken at Ieast 50 cm lower than the depth of moisture movement.

The foundations should be constructed during dry season. Also suilable plinth protection around the external wall should be made on the ground surface, with its slope away from the wall, so that moisture does not penetrate the foundation during rainy season.